Publisher review:Echo3 is the next-generation of the Echo Web Framework, a platform for developing web-based applications that approach the capabilities of rich clients. Echo3 is the next-generation of the Echo Web Framework, a platform for developing web-based applications that approach the capabilities of rich clients.
The 2.0 version holds true to the core concepts of Echo while providing dramatic performance, capability, and user-experience enhancements made possible by its new Ajax-based rendering engine. Echo2 removes the developer from having to think in terms of "page-based" applications and enables him/her to develop applications using the conventional object-oriented and event-driven paradigm for user interface development. Knowledge of HTML, HTTP, and JavaScript is not required.
Applications may be hosted using any Java servlet container. Echo2, like its predecessor, is open-source software distributed under the terms of the Mozilla Public License (or, if preferred, the GNU LGPL License).
New Features in the Current Version:
- Class-based JavaScript Inheritance: The Echo3 Core.JS module provides the capability to use class-based (rather than instance-based) inheritance in JavaScript.
- Abstract JavaScript Properties: The Core.JS system of class definition allows for the declaration of abstract methods, ensuring concrete implementations define them.
- Virtual and Final JavaScript Properties: The class definition system enables JavaScript properties to be declared as either virtual or final, thus allowing reservation of property names and preventing derived classes from overriding internal variables found in base classes.
- Method References: The Echo3 Core JS module defines a concept of "method references" for callbacks which are used throughout the client-side framework. Method references can be used when registering event listeners on components, DOM elements, and arbitrary script objects such that generated events will be fired to a method of a specific object instance.
- DOM Event Processor: All DOM events are now handled by the Echo3 DOM event processor, enabling the use of capturing event listeners on all platforms (Internet Explorer does not natively support capturing listeners).
- Scheduler: The Echo3 Core JS module provides a window.setTimeout/Interval()-based scheduling system to invoke tasks repeatedly, after a delay, or after the current JavaScript context has completed. The scheduler supports method references, such that methods may be invoked on specific objects.
- Keyboard Navigation / Focus Management: Focus amongst components is now fully tracked. Echo does away with the practice of using sequential tab index numbers to control focus order, instead presenting next/previous element focus events to components for a more intuitive user interface. Components that have multiple "focus points" especially benefit from this feature.
- Off-screen Rendering: Infratstructure is available to provide off-screen rendering to the DOM, such that sizing calculations may be performed on rendered HTML before placing it onscreen. This method is used by the WindowPane component, for example, to automatially size title bar height.
Echo3 3.0b1 is a Java script for XML Tools scripts design by NextApp, Inc..
It runs on following operating system: Windows / Linux / Mac OS / BSD / Solaris.
Operating system:Windows / Linux / Mac OS / BSD / Solaris
Echo3 3.0b1 script details 
